On Sun, Oct 14, 2001 at 07:32:18PM -0400, Perry E. Metzger wrote:
>
> eeh@netbsd.org writes:
> > We seem to have sys_sbrk() and sys_sstk() that don't seem to do
> > anything. Why are we keeping them?
>
> Ah, a fascinating topic! Have a look some time at the several PRs I
> filed on the topic of the entire brk system. There are a number of
> oddities there, none of which have a solid explanation.
>
> All that said, someday we should make brk/sbrk merely a front end for
> mmap.
For the record, I think I originally set Perry on this wild goose
chase, after Seriously Confusing myself over the same issue. The
relevant PRs (that are still open) are:
7933 brk/sbrk are strangely implemented
7934 misc. problems remaining in brk/sbrk main page
7935 mmap(2) API incompletely documented
7937 malloc/sbrk interaction poorly documented
How, exactly, would we replace sbrk with mmap()? By keeping a s3kr1t
global that's the highest address that has ever been returned and
mapping there with MAP_FIXED? There are myriad other icky issues.
Thor